India's second Covid wave hits younger patients harder, but data gaps persist

By mid-April 2021, India was reporting one in every five Covid-19 infections occurring anywhere on Earth. The second wave was moving through the country with a velocity that dwarfed the first. But what made this surge different—whether it was hitting younger people harder, whether children faced new danger, whether the virus itself had fundamentally changed—remained largely unknown. The government had not released comprehensive nationwide demographic data. States were not making their numbers public. What existed instead were fragments: hospital observations, anecdotal reports from doctors, and a growing sense that something had shifted.

The numbers that did exist suggested a possible change in who was getting sick. In Delhi, the chief minister announced on April 13 that 65 percent of Covid patients in the city were under 45 years old, though he offered no comparison to the previous year. Doctors in Delhi hospitals said they were seeing markedly younger patients than they had in October and November, when the wards had been filled mostly with elderly people. Now it was people in their 30s. In Maharashtra, the state hit hardest by the second wave, those under 40 accounted for 48 percent of cases between January and March—roughly in line with what had been reported the year before. Yet a government official in Chhattisgarh, speaking anonymously because he was not authorized to address the press, said something more alarming: not only were younger patients arriving in greater numbers, they were arriving sicker. Deaths were occurring among people above 30 without underlying health conditions, he said. A doctor in Ahmedabad suggested a simpler explanation: the elderly might be protected by vaccination, leaving younger people more exposed.

Children presented a more troubling picture. Nearly 80,000 children across five states tested positive between March 1 and April 4, with more than 60,000 of those cases concentrated in Maharashtra in a single month. While these absolute numbers were higher than in the first wave, doctors cautioned that there was no data proving the infection rate among children had actually increased. What had changed, they said, was visibility. In the first wave, many children had been infected without showing symptoms and went undetected. Now they were symptomatic. A pediatrician at a major Mumbai hospital told the press that children were "definitely more symptomatic" than before, and that the severity of their illness had risen. Some required hospitalization for gastrointestinal infections, breathlessness, and fever. Those with stomach involvement needed intravenous fluids. Those struggling to breathe needed steroids and oxygen support.

The virus itself appeared to have changed. Across India, doctors reported that entire families were becoming infected—grandparents, parents, children, all in sequence. A professor of medicine in Maharashtra said the virus had "acquired a greater transferability." In Punjab, 81 percent of sequenced samples carried a variant first detected in the United Kingdom. Maharashtra had identified a homegrown variant in 61 percent of its sequenced samples, with mutations associated with higher transmission. The numbers bore this out. During the first wave, a single infected person had spread the virus to 30 to 40 percent of their contacts. Now, according to the director of India's premier medical institute, 80 to 90 percent of people exposed to a patient turned positive. The reproduction rate—the measure of how fast infection spreads—had climbed from 1.65 in May 2020 to 2 by April 2021.

Some doctors observed that the disease itself was manifesting more severely. Lung damage was appearing earlier, within four to five days instead of the second week. Fevers were higher. In Gujarat, hospitals were consuming twice as much medical oxygen as they had before, and patients were requiring high-flow oxygen therapy at rates that had not been seen in the first wave. Yet experts cautioned against declaring the disease more severe. India's case fatality rate had actually improved, falling from 3 percent in June 2020 to 1.3 percent by April 2021. But this offered cold comfort. A doctor in Delhi warned that if the healthcare system became overwhelmed—which was already happening in smaller cities—deaths would mount regardless of the fatality rate, simply because patients would not have access to oxygen or beds. An epidemiologist from the University of Michigan put it plainly: even a low fatality rate applied to a massive number of infections yields a massive number of deaths. Each number, she said, is a person.

One more uncertainty emerged. Doctors reported that patients were testing negative on RT-PCR tests—the gold standard for Covid diagnosis—only to show clear symptoms of the disease. When retested 48 hours later, they turned positive. In Gujarat, high-resolution CT scans revealed lung infections in patients whose RT-PCR results had been negative. The test itself, it seemed, might be missing cases. Yet experts said it was too early to draw firm conclusions. What remained clear was that the second wave was moving faster, hitting harder, and overwhelming systems designed for a slower, more predictable disease. The data gaps that had plagued the first wave persisted, leaving India fighting an enemy whose true shape remained obscured.